The major goal of the proposed research is to study the development of symmetry perception in human infants. Since symmetry is a particularly salient feature for pattern perception among adults, understanding how and when infants use information about symmetry is important. Four basic experiments will assess preference, processing (habituation), discrimination, and memory for symmetry during the first two years of life. Three additional basic experiments with infants are proposed: The first will examine the infant's perception of vertical as prototypical symmetry; the second explores the infant's perception of Gestalts; and the third investigates part-whole perception in infants. A variety of symmetrical patterns will be used, and they will be compared with repeaed and asymmetric patterns. The long-range goal of this research program is to understand better the nature of percepotion and perceptual organization in infancy, including their implications for cognitive development. Symmetry is explored as a model perceptual domain.